应用激光诱导荧光（LIF）技术对层流预混乙烯火焰中多环芳香烃（PAHs）进行在线测量，并对火焰中PAHs生成机理进行验证。实验研究发现：乙烯各火焰高度下PAHs荧光光谱峰值位置不发生转移，都在500nm左右；随着火焰高度和当量比的增加，PAHs荧光光谱强度随之增强；应用Chemkin Pro软件采用ABF、USC2和KAUST2机理对燃烧过程中生成的PAHs摩尔分数进行计算，并与实验结果进行对比，发现在ABF、USC2和KAUST2机理中1环芳香烃（A1）物质生成路径一致，三种机理能够很好地预测A1物质生成。ABF和KAUST2机理中3环芳香烃（A3）物质生成路径很不相同，但是KAUST2机理能够准确预测A3的生成。而对于2环芳香烃（A2）和4环芳香烃（A4）物质，KAUST2机理预测得更加准确。%Laser induced fluorescence (LIF) method was used to detect the polycyclic aromatic hydrocarbons (PAHs) in laminar premixed ethylene flames, and to test the models of PAHs and soot formation. The fluorescence spectra of PAHs in ethylene laminar premixed flames ranging from 300nm to 500nm can be attributed to the PAHs with one to four rings (A1-A4). The intensity of A1-A4 fluorescence was measured and the mole fraction of A1-A4 was calculated by using the premixed stagnation flame model in Chemkin Pro software combined with ABF Mech, USC Mech2 and KAUST Mech2. The fuel rich flame is obviously in favor of A1-A4 formation and the fluorescence spectra intensity of A1-A4 increase faster at high equivalent ratio. The models were examined by comparing the calculated data with the experiment results from LIF measurement. The main pathways of A1 formation in ABF Mech, USC Mech2 and KAUST Mech2 are identical, and these models can predict A1 formation well. The pathways of A3 formation in ABF Mech and KAUST Mech2 are quite different, and KAUST Mech2 can predict the formation of A3 better. Moreover, KAUST Mech2 is better than ABF Mech in predicting A2 and A4 formation, because the pathways of A2 formation and the kinetic parameters of A4 formation reactions in KAUST Mech2 are upgraded on the basis of ABF Mech.
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